Langerhans cell histiocytosis (LCH) is regarded as a clonal disease, usually carrying the activating BRAF mutation V600E. Although LCH theoretically may affect all types of human tissue and typically appears during childhood, temporal bone involvement in adult patients is exceedingly rare. We report an atypical case of a 56-year-old man as one of the oldest patients diagnosed with temporal bone involvement of a BRAF-negative LCH, which caused painless otorrhea and hearing loss. Cutaneous manifestation (multifocal multisystem LCH, also known as Letterer-Siwe disease) was later recognized incidentally. Administration of ifosfamide plus doxorubicin and mesna with supplementary irradiation resulted in a temporary remission followed by slow but constant tumor progression, which after 2.5 years became resistant to treatment with cytarabine and dasatinib. Attempts at therapy (cladribine) to achieve cure are ongoing.